Hydrocarbon and carbonaceous feedstocks can be converted into H2+CO synthesis gas mixtures with varying ratios of H2 to CO. These synthesis gas mixtures can be converted into valuable hydrocarbons and chemicals using catalytic processes. Examples of the feedstocks are coals, natural gas, oil fractions, bitumen and tar-like refinery wastes, pet-coke and various forms of biomass. Examples of the main conversion processes used to produce the synthesis gas are partial oxidation, steam reforming, auto-thermal reforming, convective reforming, carbon monoxide shift conversion, and combinations of these processes.